Werkzeug and SQLAlchemy 0.5x session

Question

Updated:

Hi all,

Going through the Werkzeug link text tutorial, got stack with creating SQLAlchemy session using sessionmaker() instead of create_session() as recommended.

Note: it is not about SA, it is about Werkzeug.

Werkzeug tutorial:

session = scoped_session(lambda: create_session(bind=application.database_engine,
    autoflush=True, autocommit=False), local_manager.get_ident)

I asked how to achieve the same using sessionmaker():

As a result guys from #pocoo RCI helped me with this:

session = scoped_session(lambda: sessionmaker(bind=application.database_engine)(),
    local_manager.get_ident)

without () at the end of sessionmaker(**args) it kept giving me an error:

RuntimeError: no object bound to application

P.S. if delete lambda it will not work.

Answer 1

sessionmaker() returns a session factory, not a session itself. scoped_session() takes a session factory as argument. So just omit the lambda: and pass the result of sessionmaker() directly to scoped_session().